Thermal circuit-closer.



R. F. SCHNEIDER. THERMAL CIRCUIT CLOSER. APPLICATION men mvis. 1914.

1,271,087. Patented July 2, 1918.

Illllfillmlmlllmhmlnnl uuhmlmll (9273 1 J'H W d 4. 2 4i /M I4 4 TTORNEYS RALPH F. SCHNEIDER, on NEW YORK, N. Y.

THERMAL CIRCUIT-CLOSER.

Specification of Letters Patent.

Patented July 2, 1918.

Application filed May 15, 1914. Serial No. 838,625.

To all whom it may concern Be it known that I, RALPH F. SCHNEIDER,

. a citizen of the United States, and a resident of the borough and county of the Bronx, city and State of New York, have invented a. certain new and useful Improvement in Thermal Circuit-Closers, of which the following is a specification. I

My invention relates more particularly to that type of thermal circuit closers commonly known as contact thermometers in which the mercury after reaching a predetermined degree is instrumental in bringing about for instance the electrical operation of an alarm. Heretofore it has been necessary to construct the tube of such thermometers with a plurality of terminals operating in conjunction with the usual bulb terminal and located at different degrees in order to provide the range of usefulness desirable and necessary in such an instrument. As the introduction of these tube terminals into said thermometers, in a manner to preserve the accuracy thereof, is a delicate and diflicult operation, said instruments have heretofore been very expensive and troublesome to manufacture. The particular object of my improvement is to overcome these difficulties and objections and to provide a contact thermometer having only one terminal in the tube thereof in addition to the bulb terminal, and constructed in a manner to permit the degree at which the alarm is actuated to be varied in a simple and ellicient manner. My inventionwill be fully described hereinafter and the features of novelty will be pointed out in the appended claims.

Reference is to be had to the accompanying drawings in which Figure 1 represents my improved thermometer in its normal condition; Fig. 2 is a similar view showing the said thermometer after the degree at which the alarm is actuated has been varied; and Fig. 3 is a similar view of another form of my improvement.

As shown in the drawings my improved thermometer comprises the customary bulb 5 and tube 6 in which a channel 7 is formed in communication with said bulb for the accommodation of the mercury column 8 in the usual way. The one or bulb terminal 9 is located in the bulb 5 so as to extend into the mercury therein in the known manner while a second single or tube terminal 10 is embedded in the tube 6 at any predeterthe instrument.

mined degree or neutral point so as to extend into the channel 7 in the path of the mercury column 8. In the form shown in Figs. 1 and 2 of the illustration the terminal 10 is located at the 90 point althou h this is only an example as will be cleai ly apparent from the description hereinafter and the tube 6 is provided with indications 11 of the customary kind which in the present example extend from zero to 90 and which in some cases may be omitted entirely as will also more clearly be brought out further on in the specification. The tube 6 as shown in the drawings is connected with a second tube 6 by means of a reduced portion 6 said second tube 0 being formed with a mercury channel 7 communicating with the channel 7 by means of what is technically known as a constriction 7? and being provided with indications 11 which commence at a figure indicating the degree at which the terminal 10 is located in the tube 6 and continue upwardly therefrom. Owing to the fact that in the illustration of my improvement as shown in Figs. 1 and 2 the said terminal 10 is located at 90 in the tube (3 the indications 11 thus begin at 90 on the tube 6*. The tubes 6 and 6 thus form continuations of each other and might be termed respectively a main section or tube and an auxiliary section or tube, an eyelet 6 being provided if desired at the free end of the tube 6 for suspending or supporting The terminals 9 and 10 may be connected in any customary way with any suitable alarm or indicating device such as an electric bell or the like, a source of electrical energy such as a battery being included in the circuit to actuate the alarm when the circuit is closed in this form of my improvement.

Inthe normal condition of the instrument in the form illustrated in Figs. 1 and 2 the mercury column8 as it rises under the in fiuence of heat will finally reach and engage the terminal 10, thus closing the circuit and sounding the alarm. This contact between the said column 8 and the terminal 10 will take place at 90 owing to the fact that the terminal 10 is located in the tube 6 at this point and the mercury column 8 is arranged to properly cooperate therewith to secure this result, so that the alarm in this case will be automatically actuated when 90 of heat has been reached in the vicinity of the instrument. The degree at which the alarm is to be automatically sounded may be varied in the following manner. For instance it is desired to have the alarm "actu tube6. This is continued until theend of tube 6 has by the above operation been dethe mercury column 8 is opposite or registers with the indication l1 on said tube 6 designating 120 as shown in Fig. 2 after which the bulb 5 is removed from'the influence of the heat above mentioned and the thermometer permitted to cool. -That portion of the mercury column remaining in the tube 6 below the constriction'i' will thus gradually return to-its normal state and will fall until the normal .condition'of the mercury is again reached whereupon-it Wlll be found that the end of the mercury column in this normal state now stands opposite 60 in the tube 6. That portion of the men curycolumn 8 which through the heating of the bulb 5 has passed intothe tube 6 will be prevented by the constriction 7 from returning to the tube 6 as the thermometer cools so thatthe mercury column 8 in the creased in length a distance corresponding to 30. As will be readily apparent, the thermometer must now be subjected to 120 of heat before the mercury column which has been shortened 30 as described, will reach and cont-act with the terminal 10 so that in this condition of-the, instrument the alarm will be sounded at 120 instead of at 90 as before, it being of course understood that the terminals 9 and 10 have been re connected with the alarm circuit. If the alarm is to be sounded at any degree above 120 the same proceeding is followed and the column 8 .still further shortened by heating the bulb 5 to a higher degree and causing the column 8 to :rise higherin the tube o or until said column reaches theindication 11 designating thefdegree at which the alarm is to be sounded. It will of course be understood that the mercury may be caused to enterthe tube "6' .in any other manner than bythe application vof'heat to the, bulb when it is desired'to shorten the mercury column and change the .degree at which thealarm isfsounded. If the alarm isto be againsounded at90 the mercury in the. tube 6 isreturned to theitube'6 by shaking. the thermometer or in any-other Way to force it back beyondthe construction"? and thus again bring the said .column 8 lto its original height. and condition.

The arrangement so far described is intendedforsounding an alarm when theztemperature rises to a predetermined point, or

in other words is a heat alarm. When an instrument for sounding an alarm when the temperature drops to a predetermined point Fig. 3. The terminals 9 and 10 as shown diagrammatically are in circuit with batteries 12 and a relay 13, the latter controlling a circuit including a battery 14 and an alarm 15. Thus as longas the mercury column 8 remains in contact with the terminal 10the relay circuit will be closed and the alarm circuit will be maintained in an open or broken condition by said relay. As soon as a drop in temperature causes the mercury column 8 to drop below and out of contact with the terminal 10 the relay circuit will be broken and the battery circuit will b'e-closed by the relay and the alarm 15 immediately actuated. In the normal arrangement shown in Fig. 3 the alarm will accordingly be sounded as soon as the temperature drops below'70. The tube 6 in this form contains a portion of the mercury column 8 and beyond the constriction 7 is provided with a scale 11 commencing at Zero and reading upward, the length of said column in the tube '6 in cooperation with the scale 11 visibly indicating the degree below which the alarm'will be sounded. In the illustration the instrument being in its normal state, the mercury in the tube (F -thus stands at which is the degree at which the terminal 10 is located. If it'is desired to have an actuation of the alarm at a degree below the degree at which the terminal 10'is located in the tube 6 the length of the mercury column 8 in the said tube 6 is increased by simply transferring a portion of the mercury from'the tube 6 to the tube 6. This may be accomplished by shaking the instrument or in any other way and in any case increases-the length of the column 8 in the tube 6. If for instance an alarm at approxi- -'mately 40 is desired an amount of merso that said mercury will now:stand at 40 on the scale l1 indicating that an alarm will-be sounded when the temperature drops below 40.

In other words the mercury column 8 Wlll now remain in contact with the terminal 10 for a longer period than before so t-hatthe'relay circuit willxremain closed a correspondingly longer time and 0 the alarm circuit opened to sound the alarm only after the temperature drops below It will be readily apparent that by transferring more or less mercury from the tube 6 to the tube 6 the degree at which an alarm is had may be more or less lowered as desired. To again bring the instrument to its normal condition the amount of mercury which has been removed from the tube 6 is simply returned thereto in any desirable manner. When a heat alarm at a different degree from that at which the instrument is set is desired the length of the mercury column 8 in the tube 6 is decreased to cause a longer period of time to elapse before contact between the mercury column and the terminal 10 takes place, While when a frost alarm at such different degree is desired, the length of the said mercury column 8 is increased to cause a longer period of time to pass before the contact between said mercury column and the terminal 10 is broken.

it will thus be seen that the alarm may be automatically sounded through the medium of the thermometer at any desired degree either of heat or cold, within the range of the instrument by simply varying the length of the mercury column in the manner described and without necessitating any change in the terminal 10 or without necessitating a plurality of such terminals.

' The tube 6 acts as a container for the mer cury which in the one case is taken from 'the column 8 and which in the other case is added thereto and the indications 11 and 11 in cooperation with the mercury in the tube 6 designate the different degrees at which the alarm will be automatically sounded or in other words designate the degree at which the instrument is set. By locating the terminal 10 at difierent points along the tube 6 during manufac ture and arranging the mercury column 8 accordingly the degree at which the alarm in the no anal condition of the device may be sounded by the particular instrument in question may be changed. For instance said terminal 10 might be located at to cause the alarm normally to be sounded at ap proximately this point, the operation being the same as herein described when an alarm at a higher or a lower degree is desired. As the point at which the terminal 10 is located is initially determined usually by finding the neutral degree and is therefore known it will be obvious that all of the indications 11 on the tube 6 may be omitted or that said tube may be simply supplied with a single indication 11 opposite to the terminal 10 and designating the degree at which it is located.

The instrument below the constriction'7 in each form is thus a complete contact thermometer while the tube 6 is a container or attachment making it possible to desired. My improvement thus necessitates the use of only a single tube terminal in addition to the customary bulb terminal and consequently simplifies the construction of the instrument and reduces the cost thereof, while at the same time the accuracy of said instrument is more easily maintained in manufacturing same owing to the fact that only one, instead of a plurality of terminals 10 need be incorporated in the tube 6. My improved instrument may be used for any purpose or in any connection for which thermometers of the contact type are intended. It will of course be understood that means other than the constriction 7 may be provided for preventing a ready travel of the mercury from the tube 6 to the tube 6.

Various other changes in the specific construction shown and described may be made within the scope of the claims without departing from the spirit of my invention.

1 claim:

1. The combination of a thermometer, two terminals combined therewith at spaced intervals, a column having electrical conductivity and arranged to cooperate with said terminals to close an electrical circuit at a predetermined degree of temperature and means adapted to divide said column into disconnected sections whereby the degree at which closing of the circuit takes place may be varied.

2. The combination of a thermometer, two

terminals combined therewith at spaced intervals, a mercury column arranged to cooperate with said terminals whereby an. alarm is actuated at a predetermined degree of temperature and means for retaining a portion of said column whereby the effective length thereof and the degree at which said actuation takes place may be varied.

3. The combination of a mercurial thermometer, a bulb terminal and a tube terminal combined therewith, a mercury column arranged to cooperate with said terminals whereby an alarm is actuated at a predetermined degree of temperature, means for dividing said column into disconnected sections whereby the effective length thereof and the degree at which said actuation takes place may be varied and means whereby the extent of said change and the degree at which the actuation will take place is indicated.

4. The combination of a thermometer, two terminals combined therewith at spaced intervals, a column having electrical conductivity and arranged to cooperate with said terminals to close an electric circuit at a predetermined degree of temperature and Qflg'CQn striction in said-thermometer at an intermediate point beyond whichsaid column :is arranged to be forced and whereby a portion thereof -is normally retained to reduce the effective length-of said column and vary the degree at which theclosingof the'cirwhich the connection is effected may :be

varied.

6. The combination of amercurial athermometer, a bulbterminal and a tubeterminalcombined therewith and adapted to be connected by the mercury column at a :predetermined degree of temperature ;and a container into ,whichthemercury column is arranged to extend and-wherebyapredetermined portion thereof is retained and-separated from the remainder of the column to reduce the normal length of said columnand vary-the degree at which said. connection is effected.

7. A mercurial thermometer comprising a main tube; a bulb terminal and a tube-terminal combined with saidmaintube andadapted to-be connected by the mercurycolumn at a predetermined degree of temperature, an auxiliary tube connected with said main tube and adapted to receive a portion of the mercury column whereby the normallength of the latter is reducedanjd ;the degree at which the connection" between i the. terminals takes place may be varied andmeansfor preventing the ready return of the mercury from theauxihary tube to the-main tube.

'8. A mercurial thermometer comprising from}theremaindertthereof.wherebythe normial'length ofthe column .isreduced andthe degree at which the ,connection between the terminals takes place may be varied and a scale. on said aux liarytubeadapted to indi- .cate .the reduction in dength ofsaid mercury column. and thedegree at. whichsaid connection will take place after :said column .has

been reduced in length. 9. A .mercurial thermometer compr slng a main tube a bulb ,terminal. and atube terminal combined with said -main..;tube and adaptedto beconnected by the mercury column iat a predeterm ned degree. oftemperature, an auxlhary ,tube. connected w th. sa d ,lnaintube and adapted to receive-a portion ofthefmercury column whereby the normal length of the latter :is'" reduced and the degree at which the connection between the terminals takes placemay be varied, a. scale on said auxillarytube adaptedto lndlcate the reductionin length of said mercury column andthe degree at which said connect on will take place after said column has beenreducedin length. and a connection between .saidtubeswhereby that portion of the mercury in the auxiliary tube is prevented trom readily returning to the main tube In testimony whereof I- havehereunto set my hand in the presence of two subscribing Copies of this patent maybe ,obtained for five. cents,each, by addressing the Commissionero1 Patents,

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